Mid 60's Bultaco Matador Project

Looks Fantastic. Keep up the good work!

Mike

Annony, I bought the system from Powder by the Pound it's called a:

SPECTRACOAT ES01-C POWDER COATING GUN SYSTEM

It's better than the Harbor Freight, Eastwood, Sears guns, but it's not really a professional gun. It can also be upgraded in the future to use their:

PSS ES PRESSURE HOPPER AND CONSTANT FLUIDIZING HOPPER



So far I'm pretty happy with the gun.

Had some "fish-eye" problems in the past and thought it was because of a contaminated batch of black, but it reared it's ugly head again yesterday. Had to grind and repaint some parts and the next time through it came out better. We think we may have isolated the problem, but need to run some more tests to be sure.

I finished powder coating the shocks and I'm real happy with how they turned out.



They are from a 1970 BMW. I wanted to rebuild a pair of Bultaco shocks I have, but these were in much better condition so I thought I would use them for now and maybe try to fix the others later on.

Been busy working on the bike, but not going as quickly as I hoped. However it is coming along.

Cleaned up the forks and got the front wheel and brake done. Here's how that is looking:











Not real happy with where the brake cable has to go with this brake support, so I'm rebuilding it. Should have some pictures of the finished piece in a few days.

I cleaned up the rear wheel, brake and installed the new rear sprocket. Stuck everything on the bike, including the engine, so I could check alignment.

When I got the bike, the motor and wheel were attached, but there wasn't a chain. So when I wrapped a chain around the sprockets, I discovered a problem.








I knew the frame was modified and so I inquired about what changes were made, I found out the foot pegs had been reinforced. :huh Yep!

In case you are wondering, I did get the slack out of the chain and tried to run it under the "new support" and still have a problem.

Looks like I might need to modify the frame again!!

I like that it's so small/light that you have it in a bicycle clamp. haha!

Mmmh, I don't think so, you dont have the chain thigtener installed, a Bultaco should have a Chain thigtener,
there is one for the primary drive and there should be, - as I know - one for secundary chain drive too,
without tensioner the slack as you mentiones would be to big. (There shoul otherwise be no way to get
the chain proper installed, the distance between rocker axis and front sprocket axis is too long) *(1

One other thing to not, You should to warp around a bit of a rubber tube
to the rocker axis, that's what I did to my model 221 Sherpa. There You
can also see the chain thigtener

Like here:


*(1 Is the security plate for the front sprocket nut already bend down, I couldn't see this on the picture???

Here a drawing of the chain tensioner, the part with the circeld numbers 9 and 12:

What did you use to blast the engine casing? I'd like to do mine without outsourcing it but can't seem to find anything practical.
I've been looking mainly at soda blasters but I feel like I'd need something coarse to clean the cast like you did.

The only security washers I have are all messed up but I just got a new one and haven't installed it yet.

I like the idea of a chain tensioner, but I'm guessing they weren't used till 1967 or newer...

Here's some shot's of new bikes with the tensioner:







These bikes are more my vintage and I don't think they have chain tensioners on them:







I might still go with a chain tensioner rather than modify the frame, any opinions??

I tried soda but didn't like the results. I have been using glass beads for everything except the frame. I turn the pressure down to about 75-80 for aluminum and most of the steel work, but I shoot unregulated pressure for the really tough stuff. It's anywhere from 135 down to 90, where the compressor kicks back on.

I have a blast cabinet from Harbor Freight that leaks like a bad boat and it uses a syphon gun. For the frame I used really clean 70 grit sand from a brick supply place and had to use a pressurized tank system (also from Harbor Freight), outside, because the frame didn't fit in my blasting cabinet. The sand and pressure tank will strip just about anything.

I'm planning on building a bigger blast cabinet so I can do my next bike completely with glass beads, which leaves a much nicer surface, and work completely inside. Working outside really sucks!!

Bead blasting uses huge amounts of air so you really need a big compressor and if I am doing a lot of blasting I hook up a second compressor so it will keep up.

You have a support for a chain tensioner, I personal would use him.

As already mentioned without chain tensioner and with the big rear sprocket and the "hughe distance between rocker axis and front sprocket axis, there is no chance to get it work proper.

We don't have to forget the rear shock and the differences of chain
lenght you need when the rear shock is completly submerged.

Also the older bikes one had one, like this bike here:



It is maybe not original but it is a invention in matter of technic, maintance, durability and comfort.

The small version would be the installation of a chain roller on that pin like it is used on MX bikes.

By the way, the chain looks small too, surly not an 520?

The chain came off another Matador so I think it's probably right. But it's not put together yet, I just hung it on to check alignment.

Since I don't have a chain tensioner, can anybody recommend where I could get one that I could make work?

Hi Les,

I have one for you, I also have some nylon stock and maybe we can make a chain guide out of the stuff.

Dave

Cool!!

I was kind of thinking of trying to build one out of a front sprocket, but I'll come by and see what you have. Probably would work just as well, for a trials bike, and would be easier and more authentic. Also need to pick up the exhaust gasket.

It's some couple of weeks ago you posted this. Did you made any progress to your bike, still haven't seen it here in complete rebuild which would be very very nice to see!

BTW: if not no problem, I'am also not ready yet but I have the impression that I can catch up with your progress in rebuilding, which I never thought in forehand.

It's been a while... Been riding instead of building, but I have been slowly plugging away. Then I got an offer to show the bike at the motorcycle show in Seattle and got off my butt to make it presentable. Just one more day before the show.

I'll take some more pictures at the show.

Here it is almost done! need to clear coat the tank and there are a few more little nits I need to finish.

Very nice Bultaco, very nice indeed.


Just my 0,02€ opinion:

The tank optic looks very different to a Bultaco in my personal view, (big fan of Bultaco I have a Bul too).
If I would do the paint job I would put more Bultaco characteristics on it, like here:









With a one angled stripe with a pointy edge at the rear end, like some models have, the fenders and the tank
match more together or only just one or two logos, (plain version).
(The photoshopping is bad had not much time).

A lot of effort into that one for sure. Just some comments for the OP to make the bike work for trials. You need some 50 mm wide footpegs to actually compete on these bikes. Also you need to get a Domino slo-turn throttle and cable for that bike before you compete. That cable will catch on every tree limb you get near like that. Hopefully you left the big dumbbell flywheel weight on the right side of the crank too. If not, put that back on before you ride too. That flywheel (not the Pursangs) is what makes a Sherpa T work so well. The fiberglass gas tanks are a leaking nightmare on Matadors,in fact most Buls. Try to get a 199 plastic tank for comp. Good luck and NO MARKS.

You also need a 26mm Mikuni carb with that Domino throttle Now you are pretty close...

No Idea if you want to come near a "racing" conversion to the Matador you have, here are some very different
Sherpas and maybe some Matadors too to view at.

From very early ones up to the 199b model, which is often very nice modded,
also a good ressource for your gas tank coloring:
(199b the last Sherpa with 6 speed gearbox, 340cc, no rear frame loop and as standard with
white frame: the very competitive version, only 1,700 where made).

http://todotrial.mforos.com/65594/4821907-sherpas-diferentes/
(Spanish trial forum)